A public relations firm in Dublin has accused Denis O’Brien of breaching a court order not to interfere with a USB stick containing a dossier on him.
The businessman believes its content is defamatory and was commissioned as part of a conspiracy to damage his reputation.
Last October, Denis O’Brien anonymously received a USB stick, which contained hundreds of files about him.
One of them describes him as "Ireland’s Berlusconi" while another describes his charitable acts in Haiti as "self-serving".
Red Flag Consulting Limited admits putting the dossier together, but says it was for a client - whose identity remains a mystery after the High Court refused an order to have it revealed.
Today, their lawyers accused Mr O'Brien of failing to comply with the original order to have the USB key handed over to his solicitors "forthwith", and not to interfere with it.
They claim it remained with a company in Rotterdam for ten days, before going to ESPION, a forensic IT firm, for two days.
Red Flag says they were not aware of this at the time, and have also raised concerns about a report detailing who had access to the key.
Mr O'Brien has been given two weeks to respond to Red Flag's queries.
